JPS58136328A - Automatic light control apparatus of ophthalmic machine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic light control device for an ophthalmological instrument, and is used, for example, in a 5-odds lamp.

A photo slit lamp is used to observe the eyeballs.
This involves not only observing with the naked eye, but also taking photographs. However, when taking photographs using a conventional photo slit lamp, it is difficult to determine the exposure, and long experience and high skill are required to obtain the appropriate exposure.

In order to eliminate the drawbacks of such conventional technology, for example,
Japanese Patent Application No. 72841 discloses a proper exposure device (prior art) for a PHOTOS\-1 lift lamp. However, in this prior art, an appropriate exposure amount calculation section, a reflected light amount calculation section, an appropriate condition calculation section, etc. are provided, and the appropriate exposure amount is controlled in a programmable manner. It was completely vulnerable to differences and the inferiority of the flash tube. In addition, even if the same part is to be photographed, the appropriate exposure varies depending on the degree of the lesion, and it is difficult to obtain good photographs if the exposure is strictly controlled. Additionally, in order to obtain photographs with an appropriate amount of brightness, it is possible to use the well-known automatic light control circuit in 35-day cameras, etc., but in the field of ophthalmology, subjects with widely varying brightness are photographed within the same screen. In many cases, if average photometry is carried out, there is a drawback that it is not possible to photograph all desired parts with proper exposure.

The primary object of the present invention is to provide an automatic light control device that can overcome these drawbacks and always provide an appropriate exposure amount.

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, an objective lens 1, an imaging lens 2, and a first Porro prism 6 are arranged on an optical axis 01, and another optical axis 0.0 parallel to the optical axis 01. A second holoprism 4, a focusing plate 5, and an eyepiece 6 are disposed above, and these components constitute a well-known microscope. Usually, a stereoscopic microscope is used for stereoscopic observation, but in this example, a monocular microscope is used for simple observation. As is well known, a slit illumination device using a slit light beam is provided near the microscope, and a photographing device 40 is disposed branching off from the optical path of the microscope.

The slit light flux emitted from the slit illumination device 30 by the observation lamp 31, the relay lens 32, the slit aperture 34, and the projection lens 65 is the front focus E1 of the objective lens 1.
Align on top! After being reflected by the iris, pupil, etc. of the subject's eye (not shown), it passes through the objective lens 1, the imaging lens 2, the Porro prisms 3 and 4, the refractive plate 5, and the eyepiece 6, and then reaches the retina E2 of the observing eye. reach

That is, when the front focal point E1 matches the iris or the like of the eye to be examined, an enlarged image of the front focal point E1 is obtained on the retina E2 of the observing eye.
This enlarged image is observed by the VC. As is well known, the slit illumination device 30 has a flash discharge tube 33 for photography conjugate to an observation lamp 31, and after the light emitted from the flash discharge tube 33 that is driven during photography is reflected by the eye to be examined, A photographic device is used to expose the film to light, but since these are all well known, they will not be discussed further here.

On the optical axis Q, there is a semi-transparent mirror 7 between the lenses 1 and 2.
is disposed, and a semi-transparent mirror 8 and a reflecting mirror 9 are disposed below it. The forward oblique angles of these six mirrors 7, 8, and 9 are made equal, and one of the semi-transparent mirror 8 and the reflecting mirror 9 (on the right in FIG. 1) is provided with an imaging lens 10'& and 11 are the respective optical axes o, , o4'i, and the optical axis 01 of the objective lens 1.
The cast is made to match. and both imaging lenses 1
Further behind 0 and 11, a photometric device 20 is provided.

The photometry device [20 is a guide plate 20 that is moved in the X direction and the Y direction orthogonal to each other in the common continuation focal plane of the imaging lenses 10 and 11 by a well-known X-Y drive mechanism (not shown).
1, a light receiving element 14 is fixed to the back focal point of the imaging lens 10, and a light emitting element 15 is fixed to the guide plate 20' at the rim of the imaging lens 11. In the InnoF, when the light emitting element 15 is turned on, an image of the light emitting element 15 is formed at the front focal point E1 of the objective lens 1.

After the image of the light emitting element 15 is reflected by the eye, it is observed by the observing eye overlapping the eye to be examined, and the moat of the light emitting element 15 and the light receiving element 14 on the eye to be examined are Since the relationship is conjugate (the light-emitting element 14 is arranged at a position conjugate with the photometry site, that is, the light-receiving probe 15, and a position conjugate with the light-receiving probe 15), the photometry site is located at the light-emitting element 'f-' on the subject's eye. 2L is visually recognized as the position of the image of No. 15. Therefore, if the shutter button is turned on after the light emitting element 15 is turned off, the photographic device 4
After the shutter of No. 0 is opened, the control path 37 is operated so that the flash discharge tube 33 emits a flash of light, and the reflected light from the eye to be examined at the position where the image of the light emitting element 15 was overlapped enters the light receiving element 14. A peripheral integration circuit 38 performs light intensity integration,
When the integral amount corresponds to the proper flashlight determined by the film curvature, etc., the control circuit 37 stops the flashing of the flash discharge tube in response to a signal from the st component circuit 38, and then the shutter is closed.

Therefore, a photograph is taken in which the position where the images of the light emitting elements 15 overlap is properly exposed. Information board 20°・
is movable in the X and Y directions in the figure, and therefore,
The observer moves the guide plate 20' so that the position of the image of the light emitting element 15 coincides with the desired exposure position of the subject's eye (at this time, the optical axis O8j o4 is in the same direction and at the same angle with respect to the optical axis 0). The light-emitting confectionery 15 and the light-receiving element 14 are always conjugated in the plane to the front focus of the objective lens 1, so the observer can take a properly exposed photograph at any position. It becomes possible to photograph JIIc.

Next, an optimal example of the photometric device 20 based on the second cap will be described in detail. - A partition part 16a is formed in the space of the box-like member 16 whose sides are open, and an imaging lens is formed on the partition part 16a in the vertically spaced apart holes 161b and 16c. 12 and 13 are attached.

In addition, a light receiving element 14 and a light emitting element 15 are mounted on a plate 21 fixed to the side wall of the box-shaped member 16 while being spaced apart from each other in the vertical direction, and a plate 22 fixed to the open end thereof is mounted. Pinholes P1 and P2 are formed in.

In the initial position, the pinhole P5, the lens 12 and the light receiving element 14 are arranged on the optical axis 06 of the imaging lens 10, and the pinhole P2, the lens 13 and the light emitting element 1
5 is disposed on the optical axis 04 of the imaging lens 11.

A box-like member 1 is provided between the box-like member 16 and the fixing member 19.
A front end portion of the running lever 23 is provided with a bearing portion 18 that allows movement in the Y direction and a bearing portion 17 that allows movement in the X direction, and whose intermediate spherical portion 25a is fitted to the fixing member 19. 23b passes through the hole 18a of the fixing member 18 and fits into the hole 16d of the box-shaped member 16.

Next, the operation Q of an embodiment using the photometric device 20 of FIG. 2 in place of the photometric device 20 of FIG. 1 will be explained.

First, a slit light emitted from a slit illumination device is made incident on a specific part of the subject's eye, and an observer observes the state of the subject's eye at that time.

Next, while looking through the finder, the observer swings the grip part 2 to 6c of the set meal lever 23 in the X direction or the Y direction to emit light from the light emitting element 15. The beam of light is made to enter a specific part of the eye to be examined (for example, the same part of the eye where the slit light is incident). That is, when the lever 23 is swung to the point Q, the box-shaped member 16 moves in a predetermined direction within the XY plane, and the nfl light emitted from the light emitting element 15 is transmitted through the lens 13, the pinhole P2, and the lens 11. is reflected upward by the transmitted wave reflecting mirror 9.
, passes through the semi-transparent mirror 8, is further reflected forward by the semi-transparent mirror 7, passes through the lens 1, and forms an image on a specific portion of the subject's eye within the front focal plane of the objective lens 1.

On the other hand, the reflected light from the specific part of the subject's eye passes through the lens 1, passes through the semi-transparent mirror 7, becomes observation light, is reflected downward, is reflected by the semi-transparent mirror 8, and is reflected by the lens 10,
After passing through the pinhole P3 and the lens 12, it reaches the light receiving element 14. The light emitting element 15 is turned on and off by a switch provided near the scanning lever 23, and then the shutter button is turned on to take a picture by automatic light control.

In addition, if the light emitting element 15 lights up and remains at fC, there may be erroneous light measurement.
Therefore, a shutter button 14 is provided in which the shutter button cannot be turned on unless the light emitting element 15 is turned off.
The shutter can be opened by the off signal 7C9, the light-emitting confectionery can be turned off by pressing the shutter button halfway, and the shutter can be opened by further suppressing operation. The subsequent operations are as described above.

The main feature of this embodiment is that the convergence position of the light emitted from the luminescence g (ts) on the subject's eye, that is, the photometric position, can be accurately known, and the luminescence target of the discharge tube is determined by the reflectance of that part. It is automatically controlled according to the amount of gold.

Furthermore, this photometry position can be easily varied by moving the lever 23. This advantage is the same as the photometer 2 already detailed.
However, the present invention should not be limited to this, and it goes without saying that changes and improvements can be made as appropriate without departing from the spirit of the invention. -1 For example, as in the above example, the light emitting element 15 and the light receiving element 1
4 on the same plane or spaced apart from each other in the upper and lower directions is not essential. In short, light emitting element 1
5 and the light-receiving element 14 may be arranged so that the optical systems that meet i''L respectively meet at one point on the subject's eye. It is also possible to install them separately.

Having said the above, according to the present invention, it is possible to easily know which part of the subject's eye is being fully photometered at that moment, and to automatically control the exposure based on the photometry results. Therefore, even beginners can achieve the optimal exposure for the observation position of the eye to be examined, regardless of differences in the reflectance of the eyeball between individuals or variations in reflectance due to lesions on the eyeball of a particular person. This brings about the effect of making it possible to take good pictures.

[Brief explanation of the drawing]

FIG. 1 is a principle diagram showing the principle of the present invention, and FIG. 2 is a sectional view showing details a (embodiment) of the photometric device. [Explanation of the symbols of the main parts] Objective lens ----------------------1--- −−−−−−−−−−−−−−−−−−−−−−−
−−−−−−−−−−6 mirror −−1−−−−−−−−−
−−−−−−−−−−−−−−−−−−−−−−−−−−
-7, 8, 9 imaging lens---1---------
------ioa 11; 12ν13 light-receiving element -Jyuichi, -----------------
----------14 light emitting elements ----------1-
−−−−−−−−−−−−−−−−−−−−−−−−−
-is box-shaped member ---1---------
------
−−−−−−−−−−−20 scanning bars −−−−−−
−−−−−−−−−−−−−−−−−−−−25 Applicant Nippon Kogaku Kogyo Co., Ltd.

Claims (1)

[Scope of Claims] An automatic light control device for an ophthalmological instrument that automatically controls the light emission time of a flash discharge tube for photography based on the output of a light receiving element that receives light on an image plane, wherein the light receiving element is a partial metering device. - configuring a photometric optical system to emit light, and arranging a light emitting element for illuminating the photometric area at a position conjugate to the photometric area in front of the objective lens;
An automatic light control device characterized in that an interlocking means is provided that allows the light emitting element and the light receiving element to move while maintaining the full conjugate relationship in a plane perpendicular to the optical axis.